AT + i Protocol

The AT+i™ Protocol was developed by Connect One to provide a simple way to program an application for Internet connectivity. It eliminates the need for Internet programming and is a key element of the Internet Controller concept. Since we introduced the AT+i Protocol in 1999 and made it available in the public domain, it has become the industry-standard protocol for connecting non-PC devices to the Internet.

Enabling Widespread Internet Connectivity
Whether a device uses an Internet Controller or runs the Internet connectivity directly from the host controller, Internet programming is required to make the connectivity work - which can be a complex and lengthy process. At Connect One, we realized that a simplified, high-level API (Application Program Interface) that eliminates the need for complex Internet programming would be vital to the successful proliferation of Internet-enabled devices.

We defined a protocol for the iChip-to-host CPU and iChip-to-PHY interface that reduces the complexity of the Internet protocol suite to simple, intuitive commands. The result: minimal effort and resources are required to program the host processor for Internet connectivity.

The AT+i Protocol, an embedded TCP/IP API, is an Internet extension to the renowned Hayes AT command set that is standardized in practically all modem environments today. It is based on simple, printable ASCII commands that relieve the host application from dealing with the complexities of the Internet protocols.

In the years since we introduced the AT+i Protocol, our original belief that the embedded Internet connectivity industry needed a standardized protocol for host-to-peripheral device connectivity has been borne out. The AT+i Protocol has enabled many manufacturers to rapidly IP-enable new and existing products and has been copied by many competitors.

An API that Supports all Platforms and Protocols
iChip™ firmware includes the Internet protocols and scripts for connecting devices to IP networks via a wide range of physical media and an equally broad range of Internet protocols. All negotiation with the ISP is handled by iChip in the background, so that the user does not have to deal with this. For this reason, AT+i commands require very few modifications to the host application. In fact, iChip's SerialNET™ mode eliminates all Internet programming by packetizing serial data received on-the-fly from the host device and sending it to a remote IP address via email, HTTP, or TCP/UDP sockets.

The AT+i Protocol is communication platform-independent, enabling the host application to issue similar commands whether connected via a dial-up modem, cellular modem, wired or wireless LAN. The AT+i Protocol also is extendable, and Connect One is constantly adding new features and functionality to it.

The iChip Internet Controller is easily configured via intuitive one-time commands and configuration parameters using the "AT+i" prefix. When iChip receives an AT+i command from the host application, it enters Internet mode and commands the communication medium to access the Internet via the specified Internet protocol and PHY. If the host application issues an AT command, iChip enters Transparent mode, in which the host processor bypasses iChip, thus enabling direct two-way communication between the host CPU and the physical medium.

AT+i commands are available for direct socket manipulation and support of standard Internet protocols, including SMTP for text emails, MIME attachments, HTML page retrieval, Web serving, FTP file transfer, Telnet communications, and secure Internet protocols such as SS3/TLS1.0.